负反馈放大电路的等效计算法

An Equivalent Algorithm for Calculating Negative Feedback Amplifying Circuit

提出了负反馈放大电路的输入电阻、输出电阻、放大倍数的等效计算法。即先画出等效电路 ,然后利用电压源、电流源之间的变换与合并 ,对等效电路进行化简 ,从而计算出输入电阻或输出电阻。在计算放大倍数时 ,先对负反馈放大电路作单向化处理。由于此单向化处理已考虑了负反馈对输入电阻影响 ,因而从单向化后的等效电路中 ,可直接计算出闭环放大倍数。等效计算法不抽象 ,且计算精度高。

This article describes an equivalent algorithm for calculating the input resistence, output resistence and gain in the negative feedback amplifying circuit(NFAC). That means to extract an equivalent circuit for the NFAC to be calculated first, and then to take the converting and merging between voltage source and current source to simplify the equirvalent circuit in order to calculate the input resistence or output resistence. While calculating gain, it is necessary to unidirectionize the negative feedback amplifying circuit. For the effect of negative feedback to input resistance is already considered in the unidirectionizing. The closed loop gain can be calculated directly from the unidirectionized equivalent circuit. The equivalent algorithm has direct viewing and high accuracy.